Predictors of Postdeployment Functioning in Combat-Exposed U.S. Military Veterans

The role of posttraumatic stress symptoms on memory complaints and performance in active-duty service members

OBJECTIVE

Memory complaints are the most common form of cognitive limitation reported by military service members, but prior research suggests that posttraumatic stress symptoms (PTSS) may account for the link between subjective cognitive complaints and objective cognitive performance. The mechanisms underlying this relationship are largely unknown, including whether the finding applies to memory complaints and performance, which clinical dimensions are involved, and how the association varies when memory complaints are non-credible.

METHOD

Using a sample of 196 US military service members, the present study aims to address these gaps by modeling the relationship between objective memory performance and plausible/implausible subjective memory complaints, then evaluating how the association is influenced by PTSS and clinical traits commonly found within PTSS (e.g. depression, anxiety, and somatic concerns).

RESULTS

Overall memory complaints were associated with immediate and delayed recall, but both associations were fully mediated by PTSS (95% CI -0.14, -0.01; 95% CI -0.14, -0.02, respectively). Implausible memory complaints, however, were inconsistently linked to memory performance, and no PTSS mediation was observed. Of the clinical traits, only depression moderated the impact of PTSS, specifically by influencing the link between PTSS and overall memory complaints (β = -0.02, SE = 0.004, p < .001).

CONCLUSIONS

These results corroborate the importance of assessment for PTSS and depression in service members who report subjective memory complaints and highlight how targeted intervention for these conditions may play a key role in the management of memory complaints.

Inefficient Attentional Control Explains Verbal-Memory Deficits Among Military Veterans With Posttraumatic Reexperiencing Symptoms

Among individuals with posttraumatic stress disorder (PTSD), verbal learning and memory are areas of weakness compared with other cognitive domains (e.g., visuospatial memory). In this study, previously deployed military veterans completed clinical assessments of word memory and vocabulary (n = 243) and a laboratory task measuring encoding, free recall, repetition priming, and recognition of words (n = 147). Impaired verbal memory was selectively related to reexperiencing symptoms of PTSD but was not associated with other symptom groupings or blast-induced traumatic brain injury. Implicit priming of response times following word repetition was also unrelated to clinical symptoms. Instead, slowed response times during encoding explained associations between reexperiencing and memory performance. These findings are consistent with alterations in attentional control explaining PTSD-related verbal-memory deficits. Such findings have implications for understanding trauma-focused psychotherapy and recovery, which may depend on efficient attentional processing of words to alter posttraumatic reexperiencing symptoms.

Narrating life in the military: Links between veterans' narrative processing of service experiences and their posttraumatic stress symptoms and well-being

Military veterans frequently experience traumatic, highly stressful events; thus, it is especially important for them to find positive ways of making meaning from these experiences. The present study used the methods of narrative personality psychology to investigate the associations between veterans' narrative processing of highly stressful and significant events from their military service and postdischarge functioning, including posttraumatic stress symptoms (PTSS). United States military veterans (N = 154; M age = 64.28 years, 86.4% men, 57.8% deployed) completed an online survey in which they wrote narratives about one "highly stressful" and one "key scene" military service memory and completed questionnaires to assess PTSS, symptoms of depression and anxiety, functional impairment, and well-being. Narratives were coded for personal growth from the experience, themes of agency and interpersonal communion, affective tone, and coherence. In the highly stressful narratives, small-to-moderate negative associations emerged between both growth and agency and PTSS, depression and anxiety, and functional impairment; growth was also modestly positively associated with well-being. In contrast, affective tone and communion were each only associated modestly with one outcome, and coherence with none, and narrative processing of the key scene narrative was not linked with any mental health outcomes. These findings suggest that (1) the theory and methods of narrative identity research are relevant for studying trauma narratives, and (2) veterans who narrate themselves as growing from and exerting control over their most stressful service experiences may achieve better mental health and day-to-day functioning.

Childhood Trauma Differentially Impacts Depression and Stress Associations with Reintegration Challenges Among Post-9/11 U.S. Veterans

BACKGROUND

Post-9/11 veterans exhibit high prevalence of deployment stress, psychological conditions, and traumatic brain injury (TBI) which impact reintegration, especially among those with a history of interpersonal early life trauma (I-ELT). The relative importance of each risk factor is unclear.

PURPOSE

We examined major deployment and clinical exposures of reintegration challenges among veterans with and without I-ELT.

METHOD

We analyzed cross-sectional data of 155 post-9/11 veterans from the Translational Research Center for TBI and Stress Disorders study.

FINDINGS

Depression severity had the strongest association with reintegration challenges, followed by posttraumatic stress disorder (PTSD) severity, post-deployment stress, and deployment safety concerns. Deployment safety concerns had a stronger, significant association among veterans with I-ELT. In nearly every model, PTSD and depression severities were weaker for veterans with I-ELT, compared to those without.

DISCUSSION

Clinicians should consider the relative risk of concurrent clinical conditions and trauma histories when considering veterans' reintegration needs.

Coordinating Global Multi-Site Studies of Military-Relevant Traumatic Brain Injury: Opportunities, Challenges, and Harmonization Guidelines

Traumatic brain injury (TBI) is common among military personnel and the civilian population and is often followed by a heterogeneous array of clinical, cognitive, behavioral, mood, and neuroimaging changes. Unlike many neurological disorders that have a characteristic abnormal central neurologic area(s) of abnormality pathognomonic to the disorder, a sufficient head impact may cause focal, multifocal, diffuse or combination of injury to the brain. This inconsistent presentation makes it difficult to establish or validate biological and imaging markers that could help improve diagnostic and prognostic accuracy in this patient population. The purpose of this manuscript is to describe both the challenges and opportunities when conducting military-relevant TBI research and introduce the Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Military Brain Injury working group. ENIGMA is a worldwide consortium focused on improving replicability and analytical power through data sharing and collaboration. In this paper, we discuss challenges affecting efforts to aggregate data in this patient group. In addition, we highlight how "big data" approaches might be used to understand better the role that each of these variables might play in the imaging and functional phenotypes of TBI in Service member and Veteran populations, and how data may be used to examine important military specific issues such as return to duty, the late effects of combat-related injury, and alteration of the natural aging processes.

Posttraumatic stress symptomatology and abnormal neural responding during emotion regulation under cognitive demands: mediating effects of personality

Posttraumatic stress disorder (PTSD) is often complicated by the after-effects of mild traumatic brain injury (mTBI). The mixture of brain conditions results in abnormal affective and cognitive functioning, as well as maladaptive behavior. To better understand how brain activity explains cognitive and emotional processes in these conditions, we used an emotional N-back task and functional magnetic resonance imaging (fMRI) to study neural responses in US military veterans after deployments to Iraq and Afghanistan. Additionally, we sought to examine whether hierarchical dimensional models of maladaptive personality could account for the relationship between combat-related brain conditions and fMRI responses under cognitive and affective challenge. FMRI data, measures of PTSD symptomatology (PTSS), blast-induced mTBI (bmTBI) severity, and maladaptive personality (MMPI-2-RF) were gathered from 93 veterans. Brain regions central to emotion regulation were selected for analysis, and consisted of bilateral amygdala, bilateral dorsolateral prefrontal (dlPFC), and ventromedial prefrontal/subgenual anterior cingulate (vmPFC-sgACC). Cognitive load increased activity in dlPFC and reduced activity in emotional responding brain regions. However, individuals with greater PTSS showed blunted deactivations in bilateral amygdala and vmPFC-sgACC, and weaker responses in right dlPFC. Additionally, we found that elevated emotional/internalizing dysfunction (EID), specifically low positive emotionality (RC2), accounted for PTSS-related changes in bilateral amygdala under increased cognitive load. Findings suggest that PTSS might result in amygdala and vmPFC-sgACC activity resistant to moderation by cognitive demands, reflecting emotion dysregulation despite a need to marshal cognitive resources. Anhedonia may be an important target for interventions that improve the affective and cognitive functioning of individuals with PTSD.

Neuropsychological Impact of Trauma-Related Mental Illnesses: A Systematic Review of Clinically Meaningful Results

A trauma history is present in approximately 90% of adults in the United States. Comparatively, lifetime post-traumatic stress disorder (PTSD) prevalence is only 8.3% (Kilpatrick et al. Journal of Traumatic Stress, 26, 537-547, 2013). A neuropsychological understanding of trauma is essential to effective trauma-informed assessments and treatments. Prior reviews have focused on PTSD, specific neuropsychological domains, and statistically rather than clinically significant results. The current systematic review investigated standardized test performance across neuropsychological domains in participants with trauma histories and any psychiatric diagnosis. The review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. From 2350 records, the search returned 21 eligible studies: 8 for combat trauma, 2 for childhood trauma, 2 for intimate partner violence and sexual assault, 2 for accidental trauma, 1 for refugee trauma, and 6 for unspecified trauma. Mean neuropsychological scores ranged from low to high average, with one mean verbal memory score in the borderline range. These findings diverge from reports of between-group differences or experimental task performance, which suggest greater levels of static cognitive impairment. Current results are limited by lack of distinction between trauma types in the literature, a dearth of cognitive domains examined, wide use of self-report trauma measures, and publication and outcome reporting biases. Clinical implications for assessment and rehabilitation are discussed in relation to clinical significance, state versus trait based changes, intra-individual variability, changes from pre- to post-trauma, and within-group variability in resilience. Future directions are recommended in consideration of cultural factors, prospective and follow-up designs, and psychiatric diagnosis.

Associations between neuropsychiatric and health status outcomes in individuals with probable mTBI

Mild traumatic brain injury (mTBI) is a common occurrence, and may impact distal outcomes in a subgroup of individuals. Improved characterization of health outcomes and identification of factors associated with poor outcomes is needed to better understand the impact of mTBI, particularly in those with co-occurring posttraumatic stress disorder (PTSD). Participants in a data repository of the Injury and Traumatic Stress (INTRuST) Clinical Consortium (n = 625) completed functional disability [FD] and health-related quality of life [HRQOL] questionnaires, and a subset completed a neuropsychological assessment. FD and HRQOL were compared among participants with probable mTBI (mTBI), probable mTBI with PTSD (mTBI/PTSD), and health comparison participants (HC). Associations between symptoms, neuropsychological performance, and health outcomes were examined in those with probable mTBI with and without PTSD (n = 316). Individuals in the mTBI/PTSD group endorsed poorer health outcomes than those in the mTBI group, who endorsed poorer outcomes than those in the HC group. Individuals in either mTBI group performed worse than those in the HC on verbal learning and memory and psychomotor speed. Health outcomes were correlated with mental health and postconcussive symptoms, as well as neuropsychological variables. mTBI may adversely impact self-reported health, with the greatest effect observed in individuals with co-occurring mTBI/PTSD.

Symptoms of Posttraumatic Stress Rather Than Mild Traumatic Brain Injury Best Account for Altered Emotional Responses in Military Veterans

Emotional dysfunction is evident in posttraumatic stress disorder (PTSD), yet it is unclear what aspects of the disorder most directly relate to aberrant emotional responding. Also, the frequent co-occurrence of blast-related mild traumatic brain injuries (mTBIs) among recently deployed U.S. military personnel complicates efforts to understand the basis for emotional disruption. We studied a cross-sectional sample (enriched for PTSD and mTBI) of 123 U.S. veterans of wars in Iraq and Afghanistan. We measured subjective affective evaluations and peripheral psychophysiological responses to images with pleasant, neutral, unpleasant, and combat-related aversive content. When compared with other postdeployment participants, those who had combat-related PTSD rated pleasant image content as less positive (ηp2 = .04) and less arousing (ηp2 = .06), and exhibited heightened physiological responsivity to combat image content (ηp2 = .07). Symptoms of PTSD were associated with elevated skin conductance responses (β = .28), reduced heart rate deceleration (β = .44 to .47), and increased corrugator facial muscle electromyography (β = .47). No effects for blast-related mTBI were observed across any affective modulation measures. These findings point to a greater impact of PTSD symptomatology than blast-related mTBI on emotional functioning and highlight the utility of dimensional assessments of psychopathology for understanding the effects of combat-stress conditions on adjustment to civilian life.

Spontaneous neural activity differences in posttraumatic stress disorder: A quantitative resting-state meta-analysis and fMRI validation

Identifying the pathophysiology of posttraumatic stress disorder (PTSD) is a critical step toward reducing its debilitating impact. Spontaneous neural activity, measured at rest using various neuroimaging techniques (e.g., regional homogeneity [ReHo], amplitude of low frequency fluctuations [ALFF]), can provide insight about baseline neurobiological factors influencing sensory, cognitive, or behavioral processes associated with PTSD. The present study used activation likelihood estimation (ALE) to conduct the largest-to-date quantitative meta-analysis of spontaneous neural activity in PTSD, including 457 PTSD cases, 292 trauma-exposed controls (TECs), and 293 non-traumatized controls (NTCs) across 22 published studies. Five regions-of-interest (ROIs) were identified where activity differed between PTSD cases and controls: one when compared to all controls (left globus pallidus), two when compared to TECs (left inferior parietal lobule [IPL] and right lingual gyrus), and two when compared to NTCs (left amygdala and right caudate head). To corroborate these results, a second analysis was conducted using resting-state functional magnetic resonance imaging on an independent sample of 205 previously-deployed US military veterans. In this analysis, converging evidence from ReHo and ALFF showed that spontaneous neural activity in the left IPL alone was positively correlated with PTSD symptom severity. This result is consistent with theoretical accounts that link left IPL activity with PTSD-relevant processes such as processing of emotional stimuli (e.g., fearful faces) and the extent that attention is captured by salient autobiographical memories. By modeling the neurobiological correlates of PTSD, we can increase our understanding of this debilitating disorder and guide the development of future clinical innovations.